I'm watching Ghost Detective which isn't tagged as a romance but the relationship between the two leads is pretty clearly romantic, imo.  So I'm kind of looking for more like that, where it might not be tagged as a romance but the bond between the two characters is heavily implied to be romantic and is an important factor to the plot.  

Dramas where there is is some romance, romantic tension, or flirting but it's not the main focus of the drama (some of them are tagged as 'slight romance') and there would still be a plot if it was removed: 

  • My Mister (whether the feelings between the leads are romantic or platonic is open for interpretation)
  • Mad Dog
  • Ms. Perfect
  • Page Turner
  • City Hunter
  • Hello Monster
  • Misty
  • When a Snail Falls in Love (despite the title, the romance is subtle)

I haven't watched them, but Life and Life on Mars are both tagged as 'slight romance'. 

+1 for My Mister, Life on Mars

and maybe

hard nut

god gift 49 days

  • Signal | has a love story there as well.
  • Voice 2 | I'm still hoping that the main leads will get together in the third season.